The Brazilian has scored five league goals from an attacking midfield position on the left for Bernd Schuster's side to help send Real four points clear at the top of the table.
"The boss has faith in my football and plays me where I enjoy most," he told the club's website.
"People are confident in my abilities and I feel happy."
"We have an important match against Osasuna," he said.
"Great players have to play in great matches, the Barca game is like an all-star showdown and I hope to play as well as I am now.
"I'm working hard and doing what the boss asks of me. Things are going well for the team and me."